Why I don't use a bivy bag or over bag under an enclosed shelter tent tarp when camping to keep water off my sleeping bag!

Following up on a social media post I made about a video by Paul Messner, wet environments and damp sleeping bags and zipping up tent inners (he had zipped himself up inside his tent and by morning his sleeping bag was quite damp from either condensation or body moisture trying to move through the bag). My post was about venting a tent / tarp as much as possible and never doing up the inner of a tent unless you absolutely have to (the sleep system ie mat and sleeping bag keeps you warm not the inner!) due to midges or snow spindrift getting to you and always leaving the outer fly sheet door fully open unless rain is getting in or if wind is adversely affecting the integrity of the shelter then do it up but open all vents wherever possible. On my camp I was also thinking about waterproof water resistant bivy bags in a tent or fully enclosed tarp. During my most recent camp on Dartmoor, mid November, where it was very damp with on and off rain, cold temperatures of around minus 3c to plus 6c, little to no wind then some wind and high humidity I encountered condensation, quite a bit, not copious, but more than usual and more than I usually get in my shelters. I thought for the fun of it I’ll use my PHD Greenlandic overbag to keep damp off the down sleeping bag quilt. Unsurprisingly there was quite a bit of moisture (from drips and my dog shaking) on the water resistant over bag and I thought “thank goodness I am using an over bag bivy type bag in my shelter” after several hours (probably ten plus) I thought let’s have a look under it. The inside of the overbag and top of sleeping bag were both quite damp! I suspect eVent might have breathed better but is generally a bit heavier so for my use here not appropriate (it is more suited to using outside a shelter environment). I already knew the answer but thought let’s prove it is generally better to NEVER use a bivy over bag type system under a shelter that is PROPERLY vented and shelters you from all rain as they are simply not needed (in winter I do suggest taking one for emergency use if the shelter fails to keep rain off you). Testing my theory was doubly hard as the quilt was already damp to the touch, how will it ever dry in this wet environment, surely it will only get wetter by morning!? Over night the quilt dried out from my own heat pushing moisture through the bag and proper ventilation on a reasonably still night until early hours where breeze picked up a bit and more air flowed under my low pitched Trailstar. The only part still a bit damp but much drier was the very foot end (PHD do supply foot end covers for this purpose - but I didn’t miss not having mine) and the main top part of the sleeping bag that had been quite damp to the touch the night before was now completely dry! All will be in upcoming video! My conclusion is the same as it has always been! A bivy type bag is completely superfluous (indeed probably detrimental) in a shelter that keeps rain off you! You may need for snow or bugs or rain splashing in that might be different but in a shelter where none of those things can get to you which is most camps for the average person just use the sleeping bag as is. I’d go a step further and as stated by myself previously, there is no need for a waterproof resistant shell on the bag quilt either, go for the most breathable outer you can get!

CWT kit

https://1drv.ms/x/s!AgaI1HZMBslByWE6L8jHqTvQ0hrv?e=QnYCpO

Hopefully that is link to kit list 

It's 5kg but includes at least 1kg of power. 

Shelter is potentially if tarp is 500g

Pack 500g

Sleep system  mat bag etc 1000g

Clothing Inc wp and warm jacket and t shirt wind shirt etc 800g

Bits bobs one kg

Power one kg total 5kg

Plus phones gopro etc

If link works it's line B you need

Line A has all options including what I didn't take

Ultra light Cheddar trip

Cheddar....

SHELTER
Tarp DCF MLD poncho 139g
Polycro sheet 2m 80cm 41g
Stakes 7 74g
Stake bag 3g
Guy lines 7 50g

SLEEP SYSTEM
Pillow big Agnes 47g
PHD M degree 10c 355g
MLD bag liner 85g
Foam mat needle sports underlay 50g
Thermarest NXT xlite medium 392g

PACK
MLD Hell 28L inc 2 hip drink pockets 556g
Nylofume pack liner 30g

CLOTHING
PHD Wafer shirt 143g
EnlightenedEquipment Copperfield windshirt 59g
Senchi Designs leggings 73g
Liner socks in camp 40g
Towel 16g

COOKING
MSR Pocket Rocket Deluxe 82g
Fire Maple pot 164g

WATER
Plastic bottles (2) (48g) 96g
2L platy (2) each 47g  96g
Platypus quick draw 67g

FIRST AID HYGIENE REPAIR
Ziploc bag 5g
Bogler trowel 14g
Hand wipes alcohol (Inc repair kit air bed) 7g
DCF tape 6" 4g
Common Gear repair kit 13g
KT Tape small bit not added but I think worth it.
Chlorine Dioxide tabs water purification 2g
Ibuprofen CoCodamol Rene 12g
Sudocreme and Body Glide small pots 12g
Toothpaste tabs (4) 2g
Palmers lip balm 10g
Pocket knife 21g
Mini bic lighter 12g

FOOD
MLD long spoon 15g

ELECTRICALS
10,000 mAh inc one cable USBC 180g
Samsung s21 195g
Nitecore Head Torch 47g

INCIDENTALS
Oakley glasses 34g
Kestrel 5500 121g

Total 3352g

my sub 2.5kg list

SHELTER
Tarp DCF MLD poncho 139g
Polycro sheet 2m 80cm 41g
Stakes 7 74g
Stake bag 3g
Guy lines 7 50g

SLEEP SYSTEM
Pillow big Agnes 47g
PHD M degree 10c 355g
Foam mat needle sports underlay 50g
Thermarest original xlite short 211g

PACK
MLD Newt 28L inc 2 hip pockets 374g
Nylofume pack liner 30g

CLOTHING
PHD Wafer shirt 143g
EnlightenedEquipment Copperfield windshirt 59g
Senchi Designs leggings 73g
Liner socks in camp 40g
Towel 16g
MLD headnet 19g

WATER
1L platy 26g
2L platy 47g
Platypus quick draw (I never take this) 67g

FIRST AID HYGIENE REPAIR
Ziploc bag 5g
Bogler trowel 14g
Hand wipes alcohol (Inc repair kit air bed) 7g
DCF tape 6" 4g
Common Gear repair kit 13g
KT Tape small bit not added but I think worth it.
Chlorine Dioxide tabs water purification 2g
Ibuprofen CoCodamol Rene 12g
Sudocreme and Body Glide small pots 12g
Toothpaste tabs (4) 2g
Palmers lip balm 10g
Pocket knife 21g
Mini bic lighter 12g

FOOD
Borus food bag 24g
MLD long spoon 15g

ELECTRICALS
10,000 mAh inc one cable USBC 180g
Samsung s21 195g
Nitecore Head Torch 47g

Total 2438

Dan of Wildcamping.lifeUK shared a lightweight kit list and for the fun of it I will try to beat it

Dan's list coming in at 2.8kg SHELTER ● Wild Sky Gear Wolf Solo Tarp ● Polycro Groundsheet ● Mixture of 6 stakes ● Gossamer Gear Stake bag ● 4x Guylines SLEEP SYSTEM ● Sea To Summit Aeros Pillow ● Modified Thermarest Z-lite Foam Pad ● Enlightened Equipment Enigma 50F Quilt PACK ● ULA Equipment Photon Ultra 35L Pack ● Nylofume Pack Liner CLOTHING ● Enlightened Equipment Torrid Jacket ● Montane Featherlite Nano Jacket ● Icebreaker 150 Tights ● Injinji Trail Socks ● Buff ● Sea To Summit Nano Head Net WATER ● Disposal Water ● CNOC Vecto 2L Bladder ● Platypus Quickdraw Water Filter FIRST AID/HYGIENE/REPAIR KIT ● Duece UL Trowel ● Common Gear Bidet ● Hand Sanitiser ● DCF Patches ● Common Gear Repair Kit. ● KT Tape ● Katadyn Forte Disinfection Tabs ● 12x Flarin Ibuprofen Tabs ● Mini Tube of Sudocrem ● T-Brush Toothpaste Tabs ● Palmers Lip Balm ● TrailBrush Toothbrush ● Small Pocket Kinfe ● Mini Bic Lighter ● Massage Cork Ball FOOD ● Custom Made Hilltop Food Pack ● Sea To Summit Titanium Long Spoon ELECTRICALS ● 10,000mAh Anker Power Bank ●Samsung s23 Ultra Phone ● Nitecore TIKI Hand Torch ● Fast Charging Cables I will make a video on my Channel Tony Hobbs Youtube trying to match or beat this list

Dartmoor set to appeal but will they...

https://youtu.be/Esfu-6hqcOA

Wild Camping with my best friend | Peak District Edition